The Taliban beheaded the kidnapped translator for an Italian journalist in southern Afghanistan yesterday, according to a spokesman whose claim was confirmed by the Afghan intelligence service.

Ajmal Naqshbandi, a freelance journalist and translator, was kidnapped along with Daniele Mastrogiacomo of the Italian daily La Repubblica and a driver in southern Helmand province on March 5. The driver, Sayed Agha, was beheaded, but Mastrogiacomo was released on March 19 in a much criticised swap for five imprisoned Taliban militants.

The Taliban made a similar demand in return for the release of Mr Naqshbandi. "We asked for two Taliban commanders to be released in exchange for Ajmal Naqshbandi, but the government did not care for our demands, and today we beheaded Ajmal in Garmsir district of Helmand province," said Shahabuddin Atal, who claimed to be a spokesman for the regional Taliban commander, Mullah Dadullah.

"When we demanded the exchange for the Italian journalist, the government released the prisoners, but for the Afghan journalist, the government did not care," Mr Atal said.

Sayed Ansari, a spokesman for Afghanistan's intelligence service, confirmed the killing and said that the Taliban executed Mr Naqshbandi on behalf of al-Qaida. "Once again the Taliban showed that they are following the steps of terrorist networks," Mr Ansari said.

The news came as officials announced that seven Nato soldiers had been killed during an anti-Taliban offensive in the south of the country. Six of the victims were Canadians who died in a roadside bomb attack. The nationality of the other soldier has not been released.

The casualties came days after more than 1,000 Nato and Afghan troops retook Sangin district in Helmand from Taliban militants. The operation was part of Nato's largest yet offensive in Afghanistan, Operation Achilles, launched last month.